Many prior art valve mechanisms for internal combustion engines have been developed in recent years. Conventional internal combustion engines used in the automotive industry use poppet valves, which intermittently open to allow intake of air and exhaust of waste gases to permit the cylinders to carry out the compression and combustion cycles of the engine. A conventional poppet valve system is spring-loaded and operates through the movements of rocker arms, lifters, push rods, and a camshaft, which camshaft is ultimately linked to the engine crankshaft.
The cycle of valve openings and closures taking place within this high pressure and temperature environment is impeded by friction or failure of parts. Furthermore, the operation of conventional poppet valves, which depends on the interaction of numerous small parts, is subjected to excessive wear and tear and includes various inefficiencies. These inefficiencies include, for example, parasitic loss in the form of reciprocating components inertia, pre-ignition due to high exhaust valve temperatures and wear of valve guides, all of which often result in excessive fuel consumption and emissions, vibration, and noise in the engine block. Moreover, the performance of each poppet valve and various components also depends upon a significant volume of oil needed for lubrication. In addition, as there are two or more poppet valves in use per cylinder, the valve bodies, lifters, pushrods, and springs in operation for each valve all have a mass that is twice accelerated and decelerated every crankshaft revolutions. These loads are continually taking power from the engine and considerably increase with the increase of engine speed. Also, the lower part of the valve stem which is exposed to inlet charge and exhaust gases works as an obstacle in which it reduces the mass of the inlet air charge and hence reduces the volumetric efficiency of the engine. Additionally, the poppet valves may require periodic adjustment or replacement of hydraulic lifters.
There have been many attempts to produce power units which would be superior to the internal combustion engine in its usual form. Some attempts have been simply to improve breathing of the reciprocating engine by alternative designs of the valve mechanism. These projects have had the object of basic improvements, and have included engines with fundamentally different geometry.
For example, U.S. Pat. No. 1,002,756 to Reynolds discloses a rotary valve disc 8 operated by miter gears 10, 11, to function with valves 14 and 15 and valve seats 13.
Another approach is disclosed in U.S. Pat. No. 1,084,410, to Drennon, in which rotary discs 12 and 15 are operated by gears 23 and 24.
One of the disadvantages associated with these prior art rotary valve mechanisms is the lack of simplicity in components and have many parts.
It is therefore a primary object of the present invention to provide a rotary valve apparatus which requires fewer components and it is simple in design, yet performs in a superior manner over the conventional poppet and prior art valves.
Notwithstanding the above, it is presently believed that there may be a significant demand in the marketplace for a rotary valve apparatus having the above-stated features of the present invention.